Expansible and retractable roofing sheet



I Oct. 2, 1928. 1,686,274

0. P. 'GREENSTREET EXPANSIBLE AND RETRACTABLE ROOFING SHEET File d Jui 11. 1926 gmnodot /a l parenslreff "Patented Oct; ,2, 192 8.

' UNITED STATES .HPATENT OFFICE.

EXFANSIEBLE AND RETRACTABLE ROOFING SHEET.

Application filed July 17,

due to alterations intemperature which ex-. is about one-fourth Zinc. if used under;

' pansion and contraction inch to every ten feet. these circumstances will buckle and after a 10 time will break at soldered joints and One object of my invention is to provide a roofing;

sheet provided with longitudinally and j transversely extending crossing corrugations or ribs so that these transverseand longitudinal corrugations will take care of expan sion and contraction and expansion and contraction will not occur at the soldered joints of the sheets. A further object is to so construct the sheet that sheetsof relatively large area may be used for roofing purposes and these sheets. may be joined by soldering so as to form a perfectly tight. roof. a Y A still further objebt is to so construct the sheet with these corrugations as to permit'the discharge. of water-downward over the sheet and prevent any tendency of the water to damup. My invention is illustrated in the accompanying'drawings wherein:--

' Figure gated roofing sheet;

Figure 2 is a plan view of a plurality of roofin sheets constructed in accordance margins the sheets;

'Figure l is a top plan view of a sheet having thetransverse corrugations slightly altered in position.--- (j F Referring to Figure 1 it will be seen that therein I have illustrated a sheet 10 which ma eon siderably larger in area than the ordinary roofing sheet, this sheet 10 being provided with the vertically and longitudinally ex-' tending upwardly bowed rib or corrugation 11 and .with a transversely extending upwardly bowed rib-or corrugation 12, this corrugation being stamped up at the intersection of the corrugations; form the longitudinally extendincg channels 13 which define the longitu nal rib and thecross -middle of. the sheet.

1 is a plan view of a single corru-' with igure 1, and joined together at their" modified manner of formingthe margins ofhave anydesired size, but is preferably 1926. serial No. 123,209.

channels 14 so that .a relatively square. protuberant portion 15 is left in the These longitudinal channels 13, constitutemeans whereby water running down the roof may pass the ribs. or corrugations 12.and"drain from one sheet downward onto the next adjacent sheet. The several sheets are joined. to each other asillustrated/in Figures 2 and 3, by soldering the sheets at their adjoining edges as atf16. As illustratedin Figure 3, the sheets are preferably formed atone mar in with. an up-wardly'curved flange or bea 17, andat the opposite margin with an upwardly curved flange 18 having the edge thereof de pressed or reversely curved as at 19. This applies to all margins of the sheets and-the --.bead v17 overlaps and lies within the reversely curved portion 19 of the next adjacent sheet and is soldered thereto.

\Vhile in Figures 1 and 2 I have illustrated a roofing sheet having a vertical corrugation with a transverse corrugation at rightangles thereto, in F igure 4 I illustrate a roofing sheet which in all other respects is the same as .the roofing sheet shown in Figures 1 and 2 but which is provided with downwardly and centrally extending corrus 'gations 12 in place of the horizontal'corrugations 12., These angular corrugations 86 12 act to direct the water coming down over 7 the sheet more positively to the center of the sheet. Preferably the longitudinal corrugations 11 and the cross corrugations 12 or 12* do not extend to the margin ofthe 90 sheet but-terminate short of the margin so as to permit the margin of the sheet to be provided with beads 17, 18 and 19. Of course, it will be understood that the sheet 10 need not be provided with thebeads or I and 19' but that the sheet flanges 17 18 flat at its margins and simmay be entirel ply slightl overlap the. adjacent sheets and be soldere thereto.

The use of sheet zinc for roofing pur- 1 d 'poses is particularly for flat roofs but this construction has not been practical for the reasons stated because of the fact that the soldered joints are very liable to break clue to buckling. VVith my construction, however, this is entirely avoided. The sheet or. section can be made in any desired size butthey should never be of such size that the lon itudinal and transverse ribs are over ten ieet apart. They may be made smal 1 however, so that these longitudinal ribs or ally disposed with relation to the hump, transverse ribs are less than ten 'feet withsaid-corrugations having their inner ends 10 out any hurt. spaced from the hump and said corruga- I claim tions having their outer ends terminating A metallic shingle consisting of a sheet at the edges of thesheet. I provided at an intermediate point with an In testimony whereof I hereunto afi'lx my upstanding hum said sheet having'corrusignature. gations formed t erein and which are radi- OLIVER P. GREENSTREET. 

